Systems and methods for visualizing interior regions of a living body are known. For example, ultrasound systems and methods are shown and described in Yock U.S. Pat. No. 5,313,949 and Webler et al. 5,485,846.
Due to dynamic forces within the body, it can be difficult to stabilize internal imaging devices to consistently generate accurate images having the quality required to prescribe appropriate treatment or therapy. There is often an attendant need to constantly position and reposition the image acquisition element. In addition, tissue and anatomic structures inside the body can contact and occlude the image acquisition element.
External imaging modalities are available. Still, these alternative modalities have their own shortcomings.
For example, in carrying out endocardial ablation procedures, fluoroscopic imaging is widely used to identify anatomic landmarks within the heart. Fluoroscopic imaging is also widely used to locate the position of the ablation electrode or electrodes relative to the targeted ablation site. It is often difficult to identify these anatomic sites using fluoroscopy. It is also difficult, if not impossible, to use fluoroscopy to ascertain that the desired lesion pattern has been created after ablation. Often, the achievement of desired lesion characteristics must be inferred based upon measurements of applied ablation power, system impedance, tissue temperature, and ablation time. Furthermore, fluoroscopy cannot readily locate the border zones between infarcted tissue and normal tissue, where efficacious ablation zones are believed to reside.